openssl s_client -connect -tls1_2
nmap --script ssl-enum-ciphers -p 443



I am trying the IdentitySamples in my own helloworld MVC project. I have added the controller, model and view codes, but when I tried to edit the user, it gives me the exception in the below line

return View(new EditUserViewModel()
            Id = user.Id,
            Email = user.Email,
            RolesList = RoleManager.Roles.ToList().Select(x => new SelectListItem()
                Selected = userRoles.Contains(x.Name),
                Text = x.Name,
                Value = x.Name

When debugging, i found that RoleManager is null. To resolve it, I need add the below line in Startup.Auth.cs


This error only came out recently and according to this post in stackoverflow, it seems a bug in Apple.

Thanks for bringing this to the attention of the community and apologies for the issues you’ve been having. This issue stems from having a copy of the expired WWDR Intermediate certificate in both your System and Login keychains. To resolve the issue, you should first download and install the new WWDR intermediate certificate (by double-clicking on the file). Next, in the Keychain Access application, select the System keychain. Make sure to select “Show Expired Certificates” in the View menu and then delete the expired version of the Apple Worldwide Developer Relations Certificate Authority Intermediate certificate (expired on February 14, 2016). Your certificates should now appear as valid in Keychain Access and be available to Xcode for submissions to the App Store.

Following Apple’s instruction, the error is resolved now.

I received this error after a XCode update recently (maybe they are not related).

To fix it, just remove the Apple account and add it again …

I have an Android project using DrawerLayout, it’s working fine except that when touching on the empty area of the drawer, the touch events are caught by views behind.

To resolve it, you can add android:clickable=”true” to the drawer view.

< xmlns:android="" android:id="@+id/drawer_layout" android:layout_width="match_parent" android:layout_height="match_parent">
    <FrameLayout android:id="@+id/content_view" android:layout_width="wrap_content" android:layout_height="wrap_content"/>
    <FrameLayout android:id="@+id/drawer_view" android:layout_width="300dp" <strong>android:clickable="true"</strong> android:importantForAccessibility="no" android:layout_height="match_parent" android:layout_gravity="left"/>

But if your drawer view is included using fragment instead of framelayout, you need add the android:clickable=”true” to the root tag of the fragment layout xml.


I have been using SourceTree Mac which is very good, both UI and performance. However, when I first tried the windows version, it’s very slow …

Below are some tips I found from stackoverflow. It improved the performance a lot.

$ git config --global core.preloadindex true
$ git config --global core.fscache true

I have subscribed Amazon Cloud Drive, but when I tried to install the Windows app in windows 7, i kept getting this error “Amazon Cloud Drive setup has stopped working”.

When I expanded the error details, I saw the following line: Problem Event Name: CLR20r3.

CLR is Command Language Runtime, which is from .Net framework, so that I suspected that the Amazon Cloud Drive App for windows required a .Net Framework which is higher than my current installed 4.0.

After I installed the .Net framework 4.5, everything is working fine.

To keep it short, Amazon Cloud Drive app for Windows requires at least .Net Framework 4.5.